Compound internal-combustion turbine plant



\ Aug. 19, 1947. F. A M. HEPPNER 2 COIPOUND INTERNAL-COMBUSTION TURB INE PLANT Filed Aug. 31, 1943 2 Sheets-Sheet 1 USEFUL MRK.

EMPZRA ENTROPY TEMP R Aug. 19, 1 47. F. A. M. HEPPNER 2,426,098

COMPOUND INTERNAL-COMBUSTION TURBINE PLANT Filed M931, 1943 2 sheezs-sneet-z Patented. Aug. 19, 19?

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COMPOUND m'rnnNAL-conmUs'rroiv 'rvnnnvn rmn'r Fritz Albert Max Heppner,

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Leamington strong Siddeley. Motors Limited, Coventry, England Application August 31, 1943, Serial-No.

In Great Britain September 3, 1942 3 Claims. (Cl. 230-l23) Of internal-combustion turbine plants-whether for Jet-propulsion purposes or for drivin a ship's propeller, an electrical generator or the like-the compound type (i. e., one having separate compound sections each including a rotating turbine section driving a compressor section) is theoretically ideal; but it is'extremely complicated mechanically, leading inter alia to difllculty in the lubrication and cooling of the bearings, and sealing problems occur on many stages particularly at large diameters.

My main object is to provide an improved compound internal-combustion turbine plant with which these difficulties will be reduced.

For an understanding of this and other objects and advantages of the invention attention should be directed to the following description in which reference is made to the accompanying sheets of diagrammatic drawings, wherein:

Figure 1 is a temperature/entropy diagram for a known form of compound turbine plant, and- Figure 2 a temperature/entropy diagram for a compound plant according to the invention; whilst Figure 3 is an axial section through half a compound plant according to the invention,

It is believed that; from a comparison of Figures l and 2, those skilled in the art will readily appreciate the thermodynamic advantages of the present invention, Figure 2 showing how useful work is taken out between all the adjacent turbine sections.

According to the main feature of the invention, work is taken out between adjacent compound sections so that the pressure at the end of a conipressor section and that at the beginning of the associated turbine section are substantially equal. Preferably the pressure at the end of a compressor section is not less than the pressure at the beginning of the associated turbine section,

' 2 the turbine sections, rotarycompressor members in each section carrying extemally-extending compressor blades and also extemally-extending turbine blades of the associated turbine sections, and stationary internally-extending compressor blades carried by shrouds between the compressor and turbine sections.

In the specific construction of Figure 3, wherein these features are shown, the compound turbine plant is for Jet-propulsion purposes, and it comprises a stationary shaft III upon which are whereby to reduce any tendency for leakage to take place from the turbine section to the associated compressor section.

The invention further consists in a compound internal-combustion turbine plant as aforesaid having axially-disposed compressor sections arranged radially within the associated turbine sections which are also axially disposed. The fluid flow is preferably in one direction through the compressor sections and in the opposite direction through the turbine sections. Such a plant, particularly on for Jet-propulsion purposes, may be of the contra-rotating type, comprising a rotary drum or shell common to all the turbine sections, 1, e., carrying internally-extending blades for all mounted, as through ball bearings II, II, compressor members l2, l3, l4 and l5, l2 representing the member of the first compressorsection and I5 that for the last section. Each compressor member carries external rows of blades l5, l6, and at least one of these rows, Ila, of blades in each section extends radially outwardly beyond stationary shrouds II, which are fast with the shaft ill, to carry a ring of turbine blades It by which the associated compressor member can be driven, this constituting a compound section. There are many more turbin blades II in a row than compressor blades in a row. Joumalled at 20, 20 is a rotary drum or shell 2| which is common to all the turbine sections, the shell carryingsets of blades 22, 22, 24 and 25 with which coact the different turbine blades It. The shrouds l'l, it will be observed, segregate the turbine sections from the compressor sections.

In the present instance, there is associated with the plant a. iet-augmenter comprising external blades 21 on the turbine shell 2| and internal blades 28 on a stationary casing 29 having outside it a, streamlined cowling 20 tapering inwardly at its rear to define the outer boundary of the jet 3! Some of the air from the augmenter is delivered through the opening 23 directly into the jet, and the rest of it is delivered by stationary, fingershaped pipes 34, which are curved through 180, tothe first compressor section, as disclosed in the specification of my co-pending patent application Serial No. 500,698 filed August 31, 1943. The outlet from the last turbine section is between the pipes 24 into the jet 3 I.

To take the axial thrust of the shell I provide labyrinths 36 and 36a, preferably multi-stage labyrinths of known form, bounding the annular 'space 31 to which air is fed along passages 31a from the point of maximum pressure. Return passages 38 lead from the labyrinth 26 to different turbine sections, and these serve for cooling the turbine shell 2 I At 40 is indicated diagrammatically a member 50 in. the combustion chamber, and at 4| a fuel 3 jet. The member 40 is stationary, and a ring of :blades 42 coacts with the inlet opening of the member, the said de being Supported from the compressor member if: of the last stage.

For driving auxiliaries I may provide a spur- ,gear 43 on the last compressor member l5 to gear with a spur-gear on a layshaitl l.

In this way I provide a contra-flow, contrarotating, jet-augmenter type of internal-combustion turbine plant with compound characteristics. No special regulating means are necessary and there is no leakage from the turbine sections to the associated compressor sections, assuming the design to be such that slightly greater pressures are obtained, respectively, in the compressor sections. The combustion chamber is stationary and the plant can be easily started up.

The compressor is shown as being in four sections each giving a compression ratio of about 2, in which case stalling in the compressor sections will not take place whilst a very high overall compression (about 16 to 1) can be obtained. Furthermore, the Mach number in the turbine and compressor is low, the mechanical stresses are low and the overall weight is very low. Optimum efliciency is provided in all conditions and perfect energy balance, whilst the plant is short and compact and there is no danger of its bursting. 'The axial thrust is taken by the air supplied to th annular space 31, theleakage air being used as a coolant.

Whilst I show at 40, 4| a diagrammatic combustion chamber primary air for which is delivered by the blades 42, a preferred form of combustion chamber is as disclosed in the specification of my co-pending application Serial No.

members interposed between said turbine sections, and means drivably connected to said contra-rotating turbine members for doing useful work, said contra-rotating turbine members being so designed that the pressure at the end of a compressor section is slightly greater than the pressure at the beginning 01 the associated turbine section, whereby leakage from the turbine sections to the associated compressor sections is substantially prevented.

2. A compound internal-combustion turbine plant of the axial flow type for jet-propulsion purposes, comprising a plurality of axial1y-arranged, rotary compressor members, a plurality of axially-arranged turbine members respectively connected to and driving said compressor members, a jet-agumenter having a rotary bladed member and a. cooperating stationary biladed member coaxial with and surrounding said compressor and turbine members, and contra-rotating turbine members interposed between said first named turbine members and drivingly connected to the rotary bladed member of the Jet-augmenter, said compressor and turbine members arranged so that the flow is in opposite axial directions therethrough.

3. A turbine plant, according to claim 2, having said compressor members arranged radially within the turbine members to which they are respectively connected.

FRITZ ALBERT MAX HEPPNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,863,143 Heinze July 19, 1932 2,213,940 Jendrassik Sept. 3, 1940 1,595,278 Woerner Aug. 10, 1926 2,241,782 Jendrassik May 13, 1941 1,056,288 MacIntosh Mar. 18, 1913 1,726,104 Harris Aug. 27, 1929 FOREIGN PATENTS Number Country Date 290,014 Great Britain May 10, 1928 385,570 France Feb. 24, 1906 

